Prankster George Clooney strikes again

The "prank" war brewing between actor George Clooney and Golden Globes hosts Tina Fey and Amy Poehler appears to have stepped up a notch.

And Clooney's co-star in The Monuments Men, actor Matt Damon, has already been inadvertently pulled into the merry conflict.

Fey and Poehler won wide acclaim for their wit while hosting this year's Golden Globes, but among their many Hollywood targets were both Clooney and Damon.

The pair described Damon as a "a garbageman" and mocked Clooney for his tendency to date younger women.

"Gravity is nominated for best film. It's the story of how George Clooney would rather float away into space and die than spend one more minute with a woman his own age," Fey said at the awards.

A week later, being interviewed on the US Today Show, Clooney threw down the gauntlet. "It's a well-crafted joke. I can appreciate that," he said. "But, they have poked the bear with a stick. Oh, they have poked the bear."

A week ago, Clooney made his move.

Writing on stationery which Clooney had printed bearing Damon's name and address, Clooney faked a letter from his friend to Fey and Poehler, in which Damon supposedly poured out his heart about their hurtful joke.

According to Clooney, who revealed the prank this week on radio, the letter said: "Look, it sounds hypocritical because I laughed at jokes about George and Leo, but that's sort of what people think about them. But when you call me a garbage man it just seems like low-hanging fruit. It seems like an easy joke. I don't want an apology or anything else. I just want you to know that my kid now calls me 'the garbage man'."

Damon was unaware of the joke until a few days later when two large fruit baskets were delivered to his home with letters attached, marked "Letter #1" and "Letter #2".

The first letter said simply: "I thought you of all people could take a joke. We're both really sorry."

The second letter was a more direct threat, addressing the suspicion both Fey and Poehler had that it was part of a ruse orchestrated by Clooney.

During an interview on The Late Show with David Letterman, Damon read the second letter. It said:

Dear Matt,

If your note is part of some George Clooney prank, as I very strongly suspect it is, you A-list amateurs are gonna have to step it the f--- up. We are not some easily confused starlets you're dealing with here. We are grown-ass professional comedians. Please accept this fruit as a token of our sincerity.

Best wishes,

Tina Fey and Amy Poehler

"I immediately knew what had happened," Damon told Letterman. "George had stationery made up with my name on it and sent them some wounded letter from me. I have no idea how many letters are out there to how many people."

Speaking on Sirius Radio this week, Clooney said the war was far from over.

"That's the appetiser and what's coming now, the main course, is pretty brutal," Clooney said.

Damon, for his part, is bowing out of the war.

"He's a fun guy, a child in many ways," he told Letterman. "[But] I have four kids. I don't have time."